Two-wire socket insulator



p 13, 1966 D. J. CRIMMINS ETAL 3, 7 ,9 3

TWO-WIRE SOCKET INSULATOR 2 Sheets-Sheet 1 Filed March 1.8; 1964 W s WWW W9C M A 5, DZ M8 QWM Ab 21 :9 1a 20 22 Sept 1966 D. J. CRIMMINS ETAL3,272,913

TWOWIRE SOCKET INSULATOR 2 Sheets-Sheet 2 Filed March i8, 1964 6 mg mw ld Q I M d 0 w m United States Patent 3,272,913 TWO-WIRE SOCKET INSULATORDavid J. Crimmins, Pennington, and Robert W. Croghan, Belle Mead, N.J.,assignors to The Thomas & Betts Co., Inc., Elizabeth, N.J., acorporation of New Jersey Filed Mar. 18, 1964, Ser. No. 352,779 7Claims. (Cl. 174-138) This invention relates to an insulator for anelectrical connecting device and more in particular to an insulatorwhich can be opened to receive an electrically conductive element and tobe closed about the element in order to retain it.

Insulators are commonly employed in an electrical connecting device inorder to support and insulate the electrically conductive elements ofthe device, such as wires and terminals, with respect to one another andthe other portions of the connecting device. For example, in aconnecting device such as a socket adapted to receive a bayonet-typelamp having two contacts at its base, the socket includes a shell membercontaining an insulator through which a pair of lead wires extend inalignment with the contacts of the lamp. In many cases the ends of thelead wires protruding from the insulator are provided with rivets orterminals adapted to engage the contacts at the base of the lamp. Inconventional sockets the insulator is formed of one piece of insulatingmaterial such -as plastic or ceramic material. In forming theconventional insulator, openings or holes are provided in order toreceive the lead wires and to position and insulate them from oneanother.

In assembling the conventional socket, the need to insert the lead wiresthrough the insulator openings and the degree of alignment requiredprevents the use of high speed or automatic assembly procedures. Thuseach of the lead wires must be carefully inserted and positioned Withinthe openings in the insulator. Where rivets or terminals are applied tothe free ends of the lead wires, the lead wires must be first passedthrough the openings in the insulator and then the rivets or terminalsapplied to the free ends of the wires. If the rivets or terminals of thelead wires are applied by automatic machines before the lead wires areinserted in the insulator, then it may be necessary to pass the entirelength of lead wire through the insulator since normally the rivet orterminal is designed to engage the insulator and consequently cannotpass through its opening. Thus heretofore, due to the one-pieceinsulator construction, automatic assembly of lead wires to socketinsulators has been prevented.

It is therefore one of the objects of the invention to provide aninsulator for an electrical connecting device which can be assembledwith a conductive element by automatic means.

It is another object of the invention to provide an insulator which isadapted to be opened to receive an electrically conductive element andsubsequently to be closed to retain it.

It is still another object of the invention to provide an insulatorwhich can be locked after being closed about an electrically conductiveelement.

It is an additional object of the invention to provide an insulator foran electrical connecting device which is adapted to guide the lead wiresthereof into their proper position during assembly.

It is also an addition-a1 object of the invention to provide aninsulator which is adapted to be opened to receive a lead wire and to beclosed about the lead wire in order to maintain it in an operativeposition and to prevent it from being withdrawn from the insulator.

It is a further object of the invention to provide an insulator which isadapted to be opened to receive a terminal and to engage the terminal asthe insulator is closed about it.

It is also a further object of the invention to provide a method for theautomatic assembly of lead wires with an insulator.

In one of the embodiments of the invention, the insulator for anelectrically conductive element comprises a pair of support memberswhich are articulated in a facing relationship with one another. Each ofthe support members is provided with a grooved portion disposed in afacing relationship with one another. At least one of the groovedportions is adapted to receive the conductive element when the supportmembers are positioned away from one another. The support members areadapted to retain the electrically conductive element within the groovedportion of each when the support members are positioned adjacent to oneanother.

In another embodiment of the invention means are provided for securingthe support members adjacent to one another in a closed position.

In still another embodiment of the invention the insulator includes anabutment member and a pair of support members pivotally attached to theabutment member adjacent to a different one of the sides thereof. Whenthe support members are positioned apart from the abutment member, theconductive elements can be received therebetween and when the supportmembers are positioned adjacent to the abutment member, the conductiveelements are adapted to be retained therebetween.

In yet still another embodiment of the invention the support members andabutment members are provided with guide portions adjacent to andinclined toward the grooved portions therein in order to direct theelectrically conductive element toward the grooved portions duringassembly.

In an additional embodiment of the invention a web extending between thesupport members serves as the means for pivotally attaching them to oneanother.

In a further embodiment of the invention the grooved portions of theinsulator are provided with means for engaging the electricallyconductive element disposed therebetween.

In still a further embodiment of the invention the insulator is adaptedto engage the terminal to maintain it in a predetermined position.

Other objects and features of the invention will become apparent in thefollowing specification and claims and in the drawings in which:

FIG. 1 is a perspective view of the insulator of the invention showingit in the closed position retaining the lead wires;

FIG. 2 is a vertical section view of a lamp socket containing theinsulator of the invention;

FIG. 3 is a perspective view of the insulator of the invention in theopened position thereof both prior and during the installation of thelead wires therein in accordance with the method of the invention;

FIG. 4 is an elevational view of the insulator in the opened positionshowing its guide portions and lock member;

FIG. 5 is an elevational view of the insulator showing it in the closedposition retaining the lead wires;

FIG. 6 is a perspective view of the insulator of the invention in itsfully opened position showing the ribs within the grooved portionthereof for engaging the electrically conductive element;

FIG. 7 is an end view of the fully opened insulator showing the accessprovided for the insertion of the electrically conductive elements;

FIG. 8 is a vertical section view of the insulator showing the leadwires adjacent to the ribs in the grooved portions prior to the closingof the insulator;

'ture adjacent to the insulator.

FIG. 9 is a vertical section view showing the insulator in its closedposition in which the ribs in the grooved portion are mechanicallyengaged with the lead wires; and

FIG. 10 is a fragmentary vertical section view showing a lug in thegrooved portion of the insulator in engagement with an opening in theterminal of the lead wire.

Insulator 10 of the'invention (FIG. 1) is adapted to receive a pair of.lead wires 11 and 12 in order to support and insulate them from oneanother as well as any struc- The insulator includes abutment member orseparator 13 which is for-med with grooved portions or grooves 14 oneach of the opposite sides thereof (FIG. 4). Separator 13 is supportedby tongue 15 attached thereto. Support members or supports 16 and 17 arepositioned at the opposite sides of separator 13 and are pivotallyattached or articulated to one another by web 18 from which extendstongue 15 of the separator.

The outer surfaces 17a and 18a of supports 16 and 17, respectively areprovided with chamfers 19 and 20, respectively, in order to provide agradual reduction in thickness of ends 21 and 22 adjacent to web 18.Insulator 10 can be fabricated from plastic material having goodinsulating characteristics such as nylon. Where plastic material of thethermoplastic type is employed, the insulator can be conveniently andeconomically manufactured by injection molding. Plastic material such asnylon is flexible in thin sections and therefore web 18 can serve as apivot or hinge connection between the supports. Similarly the thinsection of tongue 15 enables it to flexibly support separator 13. Inheavier sections plastic material such as nylon is substantially rigidand capable of maintaining dimensional accuracy. Thus support 16 andsupport 17 as well as separator 13 are enabled to maintain their formafter molding.

Groovedportions or openings 23 and 24 of supports 16 and 17,respectively, are adapted to receive the lead wires. Where lead wires 11and 12 are provided with terminals or rivets 25 and 26, respectively,supports 16 and 17 are provided with chamfers 23a and 24a, respectively,adjacent to the openings. The chamfers serve as seats for the terminals(FIG. 2). In order to facilitate the placement of the lead wires intoopenings 23 and 24, supports 16 and 17, are provided with guide portionsor inclined surfaces 27 and 28, respectively, which slope toward theopenings. In the closed position of the insulator as shown in FIG. 5,the inclined surfaces of the supports are substantially contiguous withinclined surfaces 29 and 30 of the separator. Inclined surfaces 29 ofthe separator also serve as guides for directing the lead wires towardtheir respective openings in the supports during installation of thelead wires.

The means for securing the support members adjacent to one another andthe separator in the closed position in order to retain the lead wiresincludes hook 31 extending from support 17. Upon the closure of theinsulator about the lead wires, hook 31 at its cam portion 32 engagesramp 33 and is deflected outwardly as a result of the flexibility of thehook formed from plastic material. Upon further closing of theinsulator, the hook passes beyond ridge 33a of the ramp and drops intoslot 34. Shoulder 35 adjacent to slot 34 and shoulder 36 adjacent toramp 33 serve to cage and hold hook 31 in its locked position. With thisarrangement the insulator becomes self-locking whenever the supports areurged into the closed position.

As shown in FIG. 2, the insulator of the invention can be employed withan electrical connecting device such as socket 37 which is adapted toreceive a connector of the bayonet-type such as the bayonet-base of alamp.

Thus slot 38 of the socket is adapted to engage and secure one of thestuds extending laterally from the base of the lamp. Insulator 10 of theinvention is adapted to be installed within shell 39 of the socket;Sides 40 and 41 of supports 17 and 18 are arcuate in form in order tofit snugly within the cylindrical internal surface of the shell.

In order to maintain terminals 25 and 26 of the lead wires in closecontact with the terminals of the connector or lamp base to be engagedtherewith, the insulator and consequently the terminals are urgedupwardly by spring 42 which is disposed within the shell and bears uponchange 43 adjacent to the base of the socket. Supports 16 and 17 arerelieved at the ends thereof opposite to the location of the beads toform shouldered portions 44 and 45, respectively. The shoulderedportions engage and pilot the spring with respect to the insulator. Inorder to insure polarity of the lead wires with respect to the lampbase, insulator 10 is provided with key 46 extending from side 40 ofsupport 17. The key extends into slot 47 in shell 39, therebymaintaining a predetermined position of the insulator with respect tothe shell while enabling the insulator to move in the longitudinaldirection of the shell during installation of the lamp.

Insulator 48 is shown in its fully opened position in FIG. 6. Insulator48 which substantially corresponds to insulator 10 is provided withmeans for engaging the electrically conductive element, that is ribs 49and 50 disposed in a circumferential manner in openings 51 and 52,respectively. The engaging means further includes ribs '53 extendingalong each of grooves 54 of separator 55. As shown in FIG. 8 lead wires56 and 57 which are to be inserted into insulator 48 are provided withterminals 58 and 59, respectively, connected to conductors 56a and 57a,respectively. The terminals have barrels 58a and 59a of the diagonalwrap-type which are formed about the conductors of the lead Wires.

With insulator 48 in the fully opened position as shown in FIGS. 6 and7, the lead wires with their terminals in place can be dropped intoopenings 51 and 52, whereupon insulation 56b and 57b of the lead wiresengages the ribs in the openings of the insulator as shown in FIG. 8.With the lead wires resting in the openings of the insulators and withthe terminals positioned adjacent to end portion 60 of the insulator,the insulator is ready to be closed about the lead wires. During theclosing operation, supports 61 and 62 of the insulator in which areformed openings 51 and 52, respectively, are moved toward separator 55.As this occurs the ribs within the openings and the ribs of theseparator grooves engage and deform the insulation of the lead wires asshown in FIG. 9. The engagement of the ribs mechanically locks theinsulation and the conductors therein with respect to the insulator sothat upon the application of tension to the lead wires, the force istransmitted to the insulator directly and not by way of the terminals.Thus any tendency for the terminals to be moved or loosened with respectto the conductors is eliminated. When the insulator is fully closedabout the lead wires, hook 63 (FIG. 6) locks insulator 48 in the closedposition similarly as discussed wit-h respect to insulator 10. Thus thehook can maintain the insulator closed even though the compression ofthe insulator by the ribs results in the application of opening forcesto the supports of the insulator.

In certain applications it is desirable to prevent rotation of theterminal with respect to the insulator when the parts are in theiroperative position. As shown in FIG. 10 insulator 6 4 which is similarto insulator 10 includes support 65 having lug 66 formed in opening 67adjacent to end portion 68 of the insulator. The terminal to be usedwith insulator 64, that is terminal 69, includes head portion 70, barrelportion 71 and sleeve portion 72. The barrel portion is formed intoengagement with conductors 73 and lead wire 74 while sleeve portion 72is formed into engagement with insulation 75 of the lead wire.

During assembly as support 65 is closed toward separator 76, lug 66enters into slot or opening 77 formed between head portion and barrelportion7'1. At the same time shoulder 78 is advanced adjacent to barrelportion 71 and sleeve portion 72. In this way terminal 69 is keyed intoa predetermined position with respect to insulator 64. Engagement of theinsulator to the terminal in this fashion can be convenientlyaccomplished as the insulator is closed about the terminal. Such anengagement would be impossible to achieve except by means of theinsulator of the invention since normally the openings of an insulatormust be free of lugs or shoulders to enable the lead wires to be fedthrough the openings prior to the attachment thereto of the terminals.

In accordance with the method of the invention prior to the assembly ofthe lead wires with the insulator, the insulator is placed in an openposition in which the supports are spread apart from one another and theseparator, at least to the extent shown in FIGS. 3 and 4. Thus due tothe flexible nature of web 18 the supports can be spread apart over arange of opened positions extending to a position where outside surfaces40 and 41 adjacent to ends 20 and 21, respectively, are substantiallytangential with one another. Insulator 48 is shown in the fully openedposition in FIG. 7. At this position, the insulator is urged into anapproximate T-shape so that inclined surfaces 27 and 28 face insubstantially the same direction.

In automatic assembly of the lead wires with the insulator, theinsulators are spread open and secured in the open position by means notshown. Thus once the insulator is opened, guide rails or the like canengage the supports of the insulator and maintain the insulator in anopened position until it reaches a station at which the lead wires areto be placed in or urged into the open- .ings of the supports. Thus asshown in FIG. 3, the steps of assembly in accordance with the method ofthe invention include the opening of the insulator, followed by thedelivery thereto of the lead wires. It can be understood that the leadwires can be delivered to the .insulator in a rapid manner sinceinclined surfaces 29 of the separator and inclined surfaces 27 and 23 ofthe supports guide the lead wires toward the openings in the supports.This is true whether the portion of the lead wires to be inserted in theopenings of the insulator are completely or partially stripped ofinsulation. Furthermore, the presence of rivets or terminals at the endsof the lead wires in no way interferes with the delivery of them intothe openings. :In this way the insulator and the method of the inventionmake it possible to assemble insulators and lead wires in an automaticmanner.

With the lead wires positioned within the supports of the insulator asshown in FIG. 3, the final step of assembly is the closure of thesupports about the lead wires. During closing, as the supports approachto a position adjacent to the separator, cam portion 32 of book 31passes along ramp 33 and at the final closed position of the insulator,the hook drops into slot 34 and is locked. Shoulders 35 and 36 adjacentto the hook cage it in the locked position. In the closed positionopenings 23 and 24, in conjunction with grooves 14 in the separator,form substantially cylindrical holes which extend through the insulatorand serve to retain the lead wires in position with respect thereto.

By virtue of the self-locking action of hook 31 the assembled insulatorand lead wires is secured in a closed position which is suited forsubsequent automatic assembly operations related to the insulation ofthe insulator and lead wires into shell 39 of socket 37. During thisassembly operation, key 46 of the insulator is engaged with slot 47 inthe shell to insure the proper polarity of the lead wires with respectto the socket.

It is to be appreciated that the embodiments described herein are merelyintended to be illustrative of the present invention and that variationsmay be made thereon by one skilled in the art without departing from thespirit and the scope of this invention.

What is claimed is:

1. An insulator for a pair of electrically conductive elementscomprising an abutment member, a pair of support members, each of saidpair of support members being pivotally attached to said abutment memberadjacent to one end portion thereof and facing a different one of theopposite sides thereof and having a grooved portion in a facingrelationship with one another, each of said support members having aguide portion adjacent each side of said grooved portion therein andinclined thereto, said guide portions of each of said support membersbeing adapted to direct said electrically conductive element into saidgrooved portion adjacent thereto, each of said support members whenpositioned spaced apart from said abutment member being adapted toreceive a conductive element between said support member and saidabutment member into said grooved portion and when positioned contiguouswith a different one of the opposite sides of said abutment member toretain said conducting element between said support member and saidabutment member in said grooved portion.

2. An insulator for a pair of electrically conductive elementscomprising an abutment member having a pair of oppositely disposed sideseach having a grooved portion disposed therein, the portions of saidabutment member adjacent said grooved portion therein sloping therefrom,said sloping portions being disposed at a predetermined angle to oneanother, and a pair of support members, each of said support membersbeing pivotally attached to a different one of the opposite sides ofsaid abutment member and having an additional grooved portion in afacing relationship with the relieved portion in the side of saidabutment member adjacent thereto, each of said support members having aguide portion adjacent each side of said additional grooved portiontherein and inclined thereto, said guide portions being adapted todirect said electrically conductive element into said grooved portionadjacent thereto, said guide portions of each of said support membersbeing disposed at an angle with respect to one another which iscomplementary to said predetermined angle, each support member and saidabutment member when positioned apart from one another being adapted toreceive a conductive element therebetween and when positioned inengagement with one another being adapted to retain said conductiveelement therebetween.

3. In an electrical socket device having a shell member for receiving apair of conductive elements, the combination comprising an insulatordisposed in said shell member, said insulator including an abutmentmember having a pair of oppositely disposed sides each having a relievedportion disposed therein, a pair of support members, each of saidsupport members being pivotally attached to a different one of theopposite sides of said abutment member and having an additional relievedportion in a facing relationship with the relieved portion in the sideof said abutment member adjacent thereto, each support member and saidabutment member positioned apart from one another to receive aconductive element therebetween and when positioned adjacent one anotherretaining said conductive element therebetween, and means extending fromone support and engaging the other support member for securing saidsupport members adjacent one another in response to the moving of saidsupport members together.

4. An insulator for a pair of electrical terminal elements each attachedto a different electrical lead wire, each of said terminals having arelieved portion therein, said insulator comprising an abutment memberhaving a grooved portion in each of the opposite sides thereof, a pairof support members, each of said pair of support members being pivotallyattached to said abutment member adjacent to a different one of saidopposite sides thereof and having an additional grooved portion in afacing relationship with one another, at least one of each of saidgrooved portions and said additional grooved portion adjacent theretohaving a keying element disposed therein,

each of said support members having a guide portion adjacent each sideof said additional grooved portion therein and inclined thereto, saidguide portion being adapted to direct a different one of said electricalterminal elements when adjacent thereto into said grooved portion, eachof said support members when positioned spaced apart from said abutmentmember being adapted to receive a different one of said electricalterminal elements between said support member and said abutment memberinto said grooved portion and when positioned adjacent said abutmentmember to retain said electrical terminal element between said supportmember and said abutment member in said grooved portion, said keyingelement engaging the relieved portion of said electrical terminalelement adjacent thereto when said support members are positionedadjacent said abutment member.

5. An insulator for a pair of electrically conductive elementscomprising an abutment member having a pair of oppositely disposed sideseach intersected by a relieved portion disposed therein, said relievedportions dividing each of said sides into two surfaces, and a pair ofsupport members, each of said support members being pivotally attachedto one end portion thereof and facing a different one of the oppositesides of said abutment member and being intersected by an additionalrelieved portion in a facing relationship with the relieved portion inthe side of said abutment member adjacent thereto, each of saidadditional relieved portions dividing said support member into twoadditional surfaces, each support member when positioned apart from saidabutment member being adapted to receive a conductive elementtherebetween and when positioned with said additional surfacescontiguous with said surfaces of said abutment member being adapted toretain said conductive element thereebtween.

6. An insulator for a pair of electrically conductive elementscomprising an abutment member having a pair of oppositely disposed sideseach intersected by a relieved portion disposed therein, said relievedportions dividing each of said sides into two surfaces, a pair ofsupport members, each of said support members being pivotally attachedto one end portion thereof and facing a different one of the oppositesides of said abutment member and being intersected by an additionalrelieved portion in a facing relationship with the relieved portion inthe side of said abutment member adjacent thereto, each of saidadditional relieved portions dividing said support member into twoadditional surfaces, each supo rt member when positioned apart from saidabutment member being adapted to receive a conductive elementtherebetween and when positioned contiguous with a different one of theopposite sides of said abutment member with said additional surfacecontiguous with said surfaces of said abutment member being adapted toretain said conductive element therebetween, and means extending betweensaid support members for securing them together when positioned adjacentone another.

7. An insulator for a pair of electrical terminal elements each attachedto a different electrical lead wire, said insulator comprising anabutment member having a grooved portion in each of the opposite sidesthereof, the surfaces of one of said opposite sides of said abutmentmember extending away from adjacent said grooved portion therein at apredetermined included angle with respect to one another and convergingtoward the corresponding surfaces of the other of said opposite sides ofsaid abutment member, a pair of support members each of said pair ofsupport members being pivotally attached to said abutment memberadjacent to a different one of said opposite sides thereof and having anadditional grooved portion in a substantially facing relationship withsaid grooved portion adjacent thereto, at least one of each of saidgrooved portions and said additional grooved portion adjacent theretohaving a rib element disposed therein, each of said support membershaving a guide portion adjacent each side of said additional groovedportion therein and inclined thereto, the angle between the surfaces ofsaid guide portions corresponding to said predetermined included angleto enable each of said support members to mate with said abutmentmember, said guide portion being adapted to direct a different one ofsaid electrical terminal elements when adjacent thereto into saidgrooved portion, each of said support members when positioned spacedapart from said abutment member being adapted to receive a different oneof said electrical terminal elements and said lead wire attached theretobetween said support member and said abutment member into said groovedportion and when positioned adjacent said abutment member being adaptedto retain said electrical terminal element and said lead wire attachedthereto between said support member and said abutment member in saidgrooved portion as said surfaces of said guide portions engage saidsurfaces of said side of said abutment member adjacent thereto, said ribelement engaging said lead wire adjacent thereto when said supportmembers are positioned adjacent said abutment member.

References Cited by the Examiner UNITED STATES PATENTS 2,100,025 11/1937Douglas 339-188 X 2,563,604- 8/1951 Hultgren 174153 2,639,312 5/1953Kerwin 17488 X 2,727,089 12/1955 Cuccaro 174164 3,056,852 10/1962 Sachs174l53 3,057,001 10/1962 Rapata 174--153 X 3,126,184 3/1964 Kropp 174164X 3,127,471 3/1964 Greiner 174-155 X FOREIGN PATENTS 265,739 2/ 1927Great Britain. 863,386 .3/1961 Great Britain.

LARAMIE E. ASKIN, Primary Examiner.

5. AN INSULATOR FOR A PAIR OF ELECTRICALLY CONDUCTIVE ELEMENTSCOMPRISING AN ABUTMENT MEMBER HAVING A PAIR OF OPPOSITELY DISPOSEDTHEREIN, SAID RELIEVED PORTION DISPOSED THEREIN, SAID RELIEVED PORTIONSDIVIDING EACH OF SAID SIDES INTO TWO SURFACES, AND A PAIR OF SUPPORTMEMBERS, EACH OF SAID SUPPORT MEMBERS BEING PIVOTALLY ATTACHED TO ONEEND PORTION THEREOF AND FACING A DIFFERENT ONE OF THE OPPOSITE SIDES OFSAID ABUTMENT MEMBER AND BEING INTERSECTED BY AN ADDITIONAL RELIEVEDPORTION IN A FACING RELATIONSHIP WITH THE RELIVED PORTION IN A OF SAIDABUTMENT MEMBER ADJACENT THERETO, EACH OF SAID ADDITIONAL RELEIVEDPORTIONS DIVIDING SAID SUPPORT MEMBER INTO TWO ADDITIONAL SURFACES, EACHSUPPORT MEMBER WHEN POSITIONED APART FROM SAID ABUTMENT MEMBER BEINGADAPTED TO RECEIVE A CONDUCTIVE ELEMENT THEREBETWEEN AND WHEN POSITIONEDWITH SAID ADDITIONAL SURFACES CONTIGUOUS WITH SAID SURFACES OF SAIDABUTMENT MEMBER BEING ADAPTED TO RETAIN SAID CONDUCTIVE ELEMENTTHEREBETWEEN.